Platen for type-writing machines.



w. R. MULOCK. v .PLATEN FOII TYPE WRITING MACHINES.

APPLICATION FILE D MAY 'I4. 1911. v v

Patented Oct. '30, 1917] GHZOWWQA I I 1 30 that said cylinder contains the least quantity .MULOCK, a subject of the King of Great WILLIAM :annronn MULOCK, or wmmrnq, mnmrona, CANADA.

Specification of Letters Patent.

PLATEN non TYPE-WRITING MACHINES.

Patented Oct. 30, 191 '7.

Application filed May 14, 1917. Serial No. 168,433.

- To all whom it may concern:

Be" it' known that I, WILLIAM REDFORD Britain, residing at lVinnipeg, in the Province of Manitoba, Canada, haveinvented certain new and Useful Improvements in Platens for Type-Writing .Machines, of which the following is a full, clear, and ex act specification.

This invention relates to platens for type writing machines and has for its object to reduce to a minimum the noise incident to the type striking the platens.

To eliminate the noise, eachplaten should consist of a tubular layer of elastic cushionmg substance supported upon a sound dead- ,emng core, and in order to produce clear im-- pressions of the type upon the paper, it is necessary that said cushioning layer be provided with a hard covering. The hard covering is made relatively thin and divided into small parts in, order to obtain the maximum resiliency without impairing the clear- -ness of the impressions. The core consists of a thin metal cylinder filled with a sound deadening substance. This cylinder is made as thin as possible and in the form of lattice work, the interstices being ,of the largest size possible without destroying the smooth exterior surface of the cushioning tube, so

of metal necessary to giveit rigidity.

' The invention will be first hereinafter described in connection with the accompanying drawings which constitute part of this specification, and then more specifically defined in the claims at the end of the description.

i In the accompanying drawings, wherein shown on an enlarged scale for the sake o clearness', and

Fig. 2 isa transverse sectionfof the platen. In the drawings, 1 designates the metal cylinder for supporting the tubular layer of e astic cushioning substance 2. The cushioning substance used is soft rubber, and around it is wound wire 3 forming the hard surface to produce clear impressions. The wire is for the platen which is necessary in order v closely coiled or otherwise arranged to form a substantially even surface and is of fine gage so that the impact or stroke of the type W1ll b6 against-as small a hard surface as possible. The coils of the wire constitute small parts of the hard outside casing which are adapted to move independently of one another under the impact of the type by reason of the yielding quality of the elastic cushioning layer. v

The metal cylinder 1 is made very thin in order to reduce to a minimum the sound conducting substance thereof, and for the same reason it is made in the form of lattice -work with interstices therein of any desired "shape and as large as possible without imenough to preventthe tubular cushioning layer from losing its smooth exterior by being drawn or sunk into them when the wire 3 is wound upon said cushioning layer.

The sound deadening substance 4 may be soft wax, or any other suitable material, and is used merely as a fillin so as to prevent the space within the lattice cylinder from forming a resounding chamber which would be the case if said space were left open.

I Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is: y

1. A noise reducing platen for typewriters comprising in combination a tubular layer of an elastic cushioning substance, a hard outside casing surrounding the elastic cushioning layer and composed of small parts adapted to move independently of one another under the impact of the type by reason of the yielding quality of said elastic cush ioning layer, a lattice work cylinder supporting said elastic cushioning layer, and a filling ofa sound deadening substance in said cylinder.

2. A noise reducing platen for typewriters comprising in combination a tubular layer of an elastic cushioning substance, a hard outside casing surrounding the elastic cushioning layer and composed of small parts V adapted to move independently of one another under the impact of the type by reason of theyielding quality of said elastic cu hioning layer, a metal cyl nder the inner surface, of the elastic cushioning" layer and consisting of the minimum amount of metal. necessary to rigidly support said elastic cushioning layer and hard outside casing, and filling of a sound deadening substance in said cylinder.

3. A noise reducing platen for typewriters comprising 'in combination layer of elastic cushioning substance, a thin outside casing of hard material, a metal cylinder engaging the inner surface of the elastic cushioning layer and consisting of the miniminn amount of metal necessary to rigidly support said elastic Cushioning layer and hard outside casing, and afilling of a sound deadening substance in said cylinder.

4. A noise reducing platen for typewriters comprising in combination a layer of an elastic cushioning substance, an outside casing composed of a relatively thin layer of wire coiled about said elastic cushioning layer to form a substantially even surface,

a metal cylinder engaging the inner surface of the elastic cushioning layer and consisting of the minimum amount of metal necessary to rigidly support said elastic cushioning layer and hard outside casing, and a filling of a sound deadening substance in said cylinder.

5. 1%. noise reducing platen for typewriters comprising in combination a-layer of elastic cushioning substance, a. thin metal outside casing, a thin cylinder ofhard material enzip-rapes gaging the inner surface of the elastic cushioning layer for supporting the same, and a fillin; of a sound deadening substance in said cy inder.

.6. A noise reducing platen for typewriters comprising in combination a layer of elastic cushioning substance, a relatively thin outside casing of hard material, a relatively thin cylinder of hard material engaging the inner surface of the elastic cushioning layer for supporting the same, anda filling of a sound deadening substance in said cylinder for the purpose specified.

7. A noise reducing platen for typewriters comprising in combination a layer of elastic cushioning substance, a thin outside casing of hard material, and a solid core of a sound deadening substance to support said elastic cushioning layer.

8. A noise reducing platen for typewriterscomprising in combination a tubular layer of an elastic cushioning substance, a hard outside casing surrounding the elastic cushioning layer and composed of small parts adapted to more independently of one another under the impact of the type by reason of the yielding quality of said .elastic cushioning layer, and a solid core of a sound deadening substance to support said elastic cushioning layer.

In testimony whereof I have signed my name to this specification.

WILLIAM REDFORD MULOCK. 

